Ribbon-displacing device for the printing mechanism of calculating machines and the like



Feb. 21, 1967 G SCHENK 3,304,859

RIBBON-DISPLACING DEVICE FOR THE PRINTING MECHANISM OF CALCULATING MACHINES AND THE LIKE 3 Sheets-Sheet 1 Filed April 6, 1964 INVENTOR: GUSTAV SCHE/VK Feb. 21, 1967 G. SCHENK 3,304,859 RIBBON-DISPLACING DEVICE FOR THE PRINTING MECHANISM OF CALCULATING MACHINES AND THE LIKE Filed April 6, 1964 3 Sheets-$heet 2 GUSTAV SCHENK INVENTOR Feb. 21,l967

G. SCHENK 3,304,859 RIBBON-DISPLACING DEVICE FOR THE PRINTING MECHANISM OF CALCULATING MACHINES AND THE LIKE 5 Sheets-Sheet 3 Filed April 6, 1964 =22 P50 i a 29 29 g3) GUSTAV SCHENK INVENTOR Fig 4 United States Patent 3 304,859 RIBBON-DISPLACINGDEVHCE FOR THE PRHNT- ING MECHANISM OF CALCULATING MA- CHINES AND THE LIKE Gustav Schenir, Darmstadt, Germany, assignor, by mesne assignments, to Monroe Calculating Machine Company, Amsterdam, Netherlands Filed Apr. 6, 1964, Ser. No. 357,641 Claims priority, application Germany, June 14, 1963, M 57,195 16 Claims. (Cl. 101102) My present invention relates to a ribbon-displacing mechanism for machines having a plurality of type elements selectively engageable with a ribbon to imprint simultaneously one or more type-face characters upon a web such as a paper tape, strip, sheet or the like.

Machines of this type include printing calculators adapted to carry out a multitute of arithmetic operations, adding machines, tabulating machines, cash registers, read-out devices for computers and the like, all of which are characterized by having a plurality of elements adapt ed to print a selected number of type characters simultaneously. In my copending application filed concurrently herewith and entitled, Printing Mechanism for Calculating Machines, Ser. No. 357,400, now US. Patent 3,241,756, I describe a mechanism whereby any number of type elements up to the full capacity of the printing array can be actuated simultaneously to imprint numerical values with a corresponding number of places or orders. The present invention is particularly pertinent to printing calculators of the type described in this copending application although it should be noted that the principles of the invention, as will be more readily apparent hereinafter, are equally applicable to the various other machines mentioned above and all other printing devices co-operating with a ribbon and adapted to simultaneously apply a plurality of characters to a paper web or the like underlying this ribbon.

Machines of this character have, as is well known, been provided heretofore with ribbons containing a coloring substance such as ink, this ink being impregnated, for the most part, into a mesh-like support of fabric which imparts strength to the ribbon, the latter being displaceable across the array of type faces by a suitable inkribbon-advancing device. In typewriters or the like in which one character is printed at a time, this device is stepped by a distance equal approximately to the width of the type face so that repeated impressions are made with successive portions of the ribbon, thereby limiting the wear at any one location thereof. When the same principle was applied to calculating machines and the like, essentially similar devices were employed because the fabric ribbons conventionally used could receive multiple impressions at a particular location. Thus it was not too disadvantageous if, upon the printing of a relatively long number of several digits, the ribbon was advanced by a distance less than the collective width of the printing faces.

More recently, however, it has been vide single-use disposable ribbons for typewriters and the like which are discarded after a single impression and are not rerun past the printing position. Such ribbons, which generally are composed of a pigmented waxy colortransfer layer upon a substrate such as a synthetic resin film or thin paper foil, are capable of providing clean, uniform and intense impressions and are relatively inexpensive sO that the disposal of the ribbon after use is not disadvantageous in an economic sense. Those singleuse ribbons are commercially available in the form of spools of carbon-paper ribbon and suggestions have been made to employ them in the printing mechanism proposed to pro- 3,304,859 Patented Feb. 21, 1967 of multi-character printing machines. It will be readily apparent that efforts to use the conventional ribbon-advancing mechanism for disposable ribbons (this term being employed herein to identify single-use ribbons) have not been successful with printing calculators, tabulators and the like since the single-step advance of the ribbon results in some type faces engaging used portions of the ribbon with nonuniform imprinting of the type characters. The alternative suggestion that the ribbon be advanced by a distance equal to the collective Width of type faces of all of the type bars of the array is uneconomical in that printing of 1-, 2- and 3-digit numbers, for example, will require the same utilization of the ribbon as would printing of 7- or 9-digit numerals.

It is, therefore, the principal object of the present invention to provide a ribbon-displacement mechanism for a machine of the character described utilizing a disposable ribbon whereby maximum utilization of the ribbon can be obtained without the nonuniform imprinting of the type characters.

A further object of this invention is to provide, in a printing calculator or the like, a mechanism for advancing a single-use disposable ribbon of the carbon-paper type.

These objects are obtained, in accordance with the present invention, by providing a ribbon-displacement mechanism for a machine having a plurality of type elements engageable with the ribbon to imprint at least one type face or a plurality of type faces carried by the elements upon a web of paper or the like juxtaposed with the ribbon, this mechanism including feed means engageable with the ribbon for advancing it, and control means for the feed means responsive to the number of type elements actuatable in their printing positions to determine the distance of ribbon advance.

More particularly, the machine can include an array of type elements with the disposable ribbon extending along the array and actuating means for displacing a selected number of these elements against the ribbon, the control means in this case including a slidable member engageable with the type elements. When the mechanism is employed in a calculating machine of the general type described in my above-mentioned copending application or of the type described in US. Patent No. 2,905,382 to Guido Carnacina, the array of type elements has a higherorder end and a lower-order end from left to right in the normal position of use of the machine Means can be provided in machines of this type for actuating only those type bars to the right of the highest-order nonzero type bars during machine operation. In this case, the slide member can be provided with abutment means engageable with this highest-order nonzero type bar to be printed for controlling the advance of the feed means, \vhich can include a drum frictionally entraining the rib- According to a more specific feature of this invention, the drum is operatively connected with a ratchet adapted to he stepped by a pawl through a number of teeth determined by the position of the slide member along the array of type elements or bars. For this purpose, the slide member can be constituted as a stop means for the pawl having a plurality of stop surfaces staggered in the direction of displacement of the slide member from the higher order end of the array toward the lower order end of the array and selectively engageable by the pawl for determining the number of teeth by which the ratchet is stepped, the extent or degree of displacement of the member itself being determined by the particular type element engaged by its abutment means. Such a slide member can also control the actuation of the type bars as described in my aforementioned copending application.

According to a more specific feature of the present invention, the used portions of the ribbon advanced by the feed means as indicated above can be wound upon the takeup reel for discarding or, preferably, can be severed into lengths by suitable cutting means and collected in a receptacle built into the machine structure. The cutting means can thus include blade means dis-placeable transversely to the ribbon and coupled with the drum for actuation upon rotation of the latter; the blade means can be operatively connected with the drum via a cam mounted upon its shaft and rotatable therewith, a cam follower bridging the blade means and the cam.

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a somewhat diagrammatic plan view of the essential portions of the ribbon-displacement mechanism of a calculating machine according to the present invention, parts being broken away for purposes of clarity;

FIG. 2 is a coss-sectional view taken along the lines IIII of FIG. 1 with nonessential portions of the mechanism omitted;

FIG. 3 is a side-elevational View, partly in section, of the control means for the ribbon-displacement mechanism, taken along the line III-III of FIG. 1;

FIG. 4 is a fragmentary plan View similar to FIG. 1 showing the mechanism in another operative position; and

FIGS. 5 and 6 are detail top views of the ribbon-cutting portion of the device with the blade-controlling cam shown in full.

In FIGS. 1 and 2, I show an array of transfer slides 3 provided with rack teeth 3b and longitudinally slidable between the housing walls 1, 2 upon a rod 4 and a bail 50 via suitable slots So at the opposite ends of the transfer slides, one of these slots being shown in FIG. 2. As described in my above-identified copending application, the transfer slides 3 can be shifted in the direction of arrow 51 by movement of the bail St) in this direction as controlled by a suitable cam and link coupled with the drive shaft 6 of the machine. The transfer slides 3 are provided with heads 3c engageable with off-normal pins of a pin carriage 53 shiftable across the path of these slides upon rails 54, 55. In the conventional manner, a numerical value may be registered in the pin carriage by displacing pins corresponding to the digit of the respective numeral decadic order into an off-normal position, these pins constituting stops for the slides 3 when their movement in the direction of arrow 51 by respective springs (not shown) is permitted by the bail 50. The mechanism for displacing the pin carriage 53 and the transfer slides 3 is fully described in my above-identified copending application, while the pin-carriage construction can be of the type disclosed in my further concurrently filed copendi-ng application Ser. No. 357,640, entitled Pin-Carriage Assembly for Calculating Machines now abandoned. These elements are illustrated herein in FIG. 1 only to provide an indication of the general construction of the apparatus and the method by which is functions to the extent to which these elements are related to the ribbondisplacement mechanism to be described hereinafter.

Each of the transfer slides 3 corresponds to a respective order of a numeral to be printed and has its rack teeth 3b in mesh with a respective pinion gear 5 freely rotatable upon the drive shaft 6; each gear 5, in turn, meshes with rack teeth 56 of a respective type bar or element 7, these elements which are arranged in consecutive spaces along a printing position form an array parallel to the platen 9 and have type faces 8 selectively juxtaposed with a singleuse ribbon 12 of the carbon-paper type for printing the respective type characters. The type bars 7 are linearly displaceable in the direction of arrow A (FIG. 2) and may be replaced by type sectors as conventionally provided in the calculating art if desired. To effect printing of the type characters, the bars 7 are also swingably mounted for movement in the direction of arrow B in the conventional manner. A paper web or tape 11 can be juxtaposed with the ribbon 12 and disposed between the latter and the platen 9 whose shaft 11 is journaled between the housing walls 1 and 2; the shaft 10 can be stepped, for example, as described in US. Patent No. 2,905,382 mentioned above, to advance the paper past the ribbon and printing location. While the means for effecting printing of the type faces and actuating the type bars can be of any of the well-known types, in the embodiment illustrated the actuating mechanism is of the sort described in my fiirst-mentioned copending application and is illustrated herein in simplified form.

The carbon-paper ribbon or one wherein a synthetic resin foil is provided with a pigmented transfer layer, is fed from the supply reel 57, rotatable upon the support axle 58, through a guide 38 across the array of type elements 7 intermediate the latter and the platen 9 in the direction of arrow D, i.e. from the higher-order end of the array toward the lower-order end thereof. Adjacent the type-bar array on the side thereof opposite the supply reel 57, the exhausted ribbon is engaged by a feed drum 23 rotatable on its shaft 24 about a generally upright axis. A spring-loaded pressure roller 27 holds the ribbon against the feed drum 24. The drum 23 together with its shaft 24 are rotatably journaled at 25 and 26 in the machine housing and are secured to a toothed ratchet wheel 28, the latter being provided at the end of shaft 24 remote from the drum 23 (see FIG. 3).

The control means for the ribbon-displacement mechanism includes a pawl 29 of generally flat configuration displaceable in the direction of arrow 59 in a plane parallel to the axis of drum 23 but transversely thereto. The pawl 29 is provided with a tongue 29c resiliently engageable with the ratchet wheel 28 and is mounted via its slots 2% upon a pair of studs 31 springs 39 (only one of which can be seen in FIG. 1) being provided to yieldably urge the finger 29c int-o engagement with the ratchet. Upon the return stroke of the pawl 29, in a direction opposite arrow 59, the rear surfaces of the teeth of ratchet 28 cam the pawl 29 outwardly to permit the finger 290 to clear the teeth of the ratchet wheel.

At the left-hand end of the pawl, as seen in FIG. 3, an arm 29d is provided, this arm carrying a cam-follower pin 2% bearing against the eccentric periphery of an cecentric cam 31 mounted upon the drive shaft 6 and adapted to permit gradual movement of the pawl 29 in the direction of arrow 59 under the force of spring 29). R0- tation of shaft 6 during each calculating operation permits the pawl 29 to move in the direction of arrow 59 under the force of spring 29 in such manner that the finger 2%.steps the ratchet wheel 28. v

The pawl 29 is further provided with an arm 2% (FIGS. 3 and 4) which is engageable with the steps 14d of a slidable control member 14. The slide member 14 is shiftable parallel to the array of type elements but transversely to the latter upon a traverse bar 13 mounted on the side walls 1, 2. The slide member 14 is also provided with a pair of longitudinal slots 14b in which the bolts 15, connected to the traverse bar 13, serve as guide members. A tension spring 17 joined to the slide member 14 at Me urges it in the direction of arrow D against a detent 18 (FIGS. 1 and 2) in the form of a bell-crank lever. The detent 18 is pivotally mounted upon a stud 19 and has an arm 18a engageable with an abutment means 14 of the slide members 14 in its extreme lefthand position (in the normal position of use in the machine) whereby the stop-forrning steps 14d of the slide member 14 clear the pawl 29. The rest position of the slide member is illustrated in FIG. 1. The other arm of detent lever 18 is provided with a cam-follower pin 20 bearing against the cam 22 via the force of a spring 21 normally urging the detent 18 in the clockwise direction (FIG. 2) into engagement with the abutment means 14f. Cam 22 is mounted upon the main machine shaft 6 for rotation therewith. Upon rotation of the drive shaft to initiate a calculating sequence and subsequent to the shifting of the transfer slide 3 to displace the type bars 7 into their printing positions, cam 22 releases the detent 18 from engagement with the slide member 14 so that the latter can shift in the direction of arrow D under the force of spring 17.

The slide member 14 is also provided with an abutment 14c which, in the rest or zero-printing position of the type bar 7 (FIG. 2) is adapted to clear the engage ment surface 7a of these bars. When, however, one or more type bars are elevated, the abutment 14c sweeps across the array until it engages the highest-order elevated (nonzero) type bar whereupon the slide member 14 i halted (FIG. 4). All of the type bars to the right of the one engaged by the abutment 14c and this one too, are printed while those type bars to the left thereof remain unprinted. It will be apparent, therefore, that the movement of the slide member 14 is always proportional to the number of characters to be printed and thus to the length of the ribbon to be affected during a particular calculating operation.

The degree of movement of the slide member 14 also determines the particular step 14d disposed in line with the arm 2% of pawl 29 and consequently the distance by which the pawl is permitted to move upon rotation of cam 31. While it is possible to provide one step corresponding to each of the type bars of the array, it has been found that excellent results are also obtained when, say, several steps are provided for a greater number of type bars, two or more type bars being associated with each step. When it is desired to print the full capacity of the array of type bars, the slide member 14 remains in its left-hand extreme position with the abutment 14c engaging the highest order-type barof the array. In this case, the pawl 29 clears the step 14d and a full-stroke displacement of the pawl results, wit-h a corresponding stepping of the teeth of ratchet 28 and an advance of the ribbon by a distance proportional to the number of type bars actuated. When a lesser number of type bars is actuated, the abutment 14c engages the highest-order nonzero bar and a correspondingly lesser displacement of the pawl 29 and the ribbon results. In the embodiment illustrated, for a calculating machine having 7 printing bars, 4 operative steps are provided including the step in which the slide member 14 does not interfere at all with the movement of the pawl.

The actuating means for the type bar 7 may include, as mentioned above, a mechanism of the type previously described in connection with my first-mentioned copending application Ser. No. 357,400, whereby the type elements 7 are each provided with an elongated slot 60 in which a stud 61 of a respective bell-crank tripping element 62 is received. The tripping elements 62 are pivoted for limited angular displacement in the direction of arrow 63 about a shaft 64 which can be coupled with the motor shaft 6 via a conventional cam and is adapted to oscillate angularly. Tripping elements 62 are each provided with respective springs 65 normally urging them in the clockwise sense as viewed in FIG. 2. The slide member 14 can also be provided with a locking portion 14g engageable with one arm 66 of the tripping elements 62 to prevent the latter from transferring force to the respective type bar 7 in the direction of platen 9 (arrow B). Each of the tripping elements 62 can be provided with a segmental cutout 67 in which is received a key 68 affixed to the shaft 64 and forming a lost-motion connection with the radial walls of the cutout 67. When the key 68 is in its extreme counterclockwise position, the respective tripping elements 62 are maintained in their rest positions and the springs 65 are tensioned. When it is desired to print the numerical value entered into the calculator, the shaft 64 is rotated in the clockwise direction, thereby swinging the tripping elements 62 whose arms 66 are not engaged by the blocking portion 14g of the slide member 14. The respective type bars 7 are thus.

displaced in the direction of arrow B to print the respective characters upon the tape 11, all of the type bars to the right of the highest-order nonzero type bar engaged by the abutment 14c and this bar itself are thus printed while the type bars to the left thereof remain unactuated. At the conclusion of the machine cycle, continued rotation of shaft 6 can serve via a suitable cam, not shown but of the type disclosed in my first-mentioned copending application, to swing the restoring lever 70 in the counterclockwise direction (FIG. 1) by movement of a swingable element 71. Lever 70 is thus rotated about its shaft 72 and with its arm 73 displaces the slide member 14 in the direction opposite that of arrow D until the detent 18 once again engages the abutment 14 The other arm 74 of lever 70 can, by virtue of its engagement of pin 75, shift the pin carriage 53 back into its rest position (arrow '75).

While the used portion of the ribbon 12 can be wound in the conventional manner on a takeup spool not illustrated, it is preferred to sever the exhausted ribbon into lengths and collect them in a receptacle built into the machine housing (FIG. 1). The cutting means required for this purpose, as illustrated in FIGS. 1, 5 and 6, com prises a fixed blade 36 co-operating with a slidable blade 35 movable in a guide 35a and pivotally mounted upon a second-order lever 33 fulcrumed at 33a to the housing and carrying on its free extremity a cam-follower pin 33b. The latter is held by a spring 37 against the lifting cam 32 mounted upon shaft 24 intermediate the drum 23 and the ratchet 28. This cam is so arranged that, upon each complete revolution of the drum 23, lever 33 is shifted in the direction of arrow 81 so that blade 35 severs a length of ribbon corresponding to the circumference of drum 23 from the strip and drops it into the receptacle 80. The latter can be emptied from time to time.

The invention described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the appended claims.

I claim:

1. A ribbon-displacement mechanism for a machine having a plurality of type elements arranged in consecutive spaces along a printing position selectively engageable with a ribbon to imprint at least one character of a type face carried by at least one of said elements upon a web juxtaposed with said ribbon, said mechanism comprising feed means engageable with said ribbon for advancing it past said type elements; and control means for said feed means engageable with an actuated type element to sense the number of type elements actuated to imprint respective characters upon said web, for advancing said ribbon past said type elements by a distance porportional to said number of actuated type elements.

2. In a machine adapted to imprint selectively a plurality of characters upon a web, in combination:

an array of type elements arranged in consecutive spaces along a printing position selectively engageable with a ribbon extending along said array and provided with type faces corresponding to said characters for imprinting them upon a web juxtaposed with said ribbon;

actuating means for displacing a selected number of said elements against said ribbon and said web; and

a ribbon-displacement mechanism engageable with an actuated type element of said array and said ribbon for advancing said ribbon past said array by a variable distance porportional to the number of actuated type elements displaced by said actuating means.

3. In a machine adapted to imprint selectively .a plurality of characters upon a web, in combination:

an array of type elements arranged in consecutive spaces along .a printing position selectively engageable with a disposable ribbon extending along said array and provided with type faces corresponding to said characters for imprinting them upon a web juxtaposed with said ribbon;

actuating means for displacing a selected number of said elements against said ribbon and said web; and

a ribbon-displacement mechanism engageable with said ribbon for advancing it past said array by a variable distance determined by the number of type elements displacedby said actuating means, said ribbon-displacing mechanism including feed means engageable with said ribbon for displacing same, and control means responsive to an actuated type element to sense a number of type elements of said array for selectively varying said distance advanced by said ribbon in porportional to the number of type elements displaced by said actuating means.

4. In a machine adapted to imprint selectively a plurality of characters upon a web, in combination:

an array of type elements selectively engageable with a disposable ribbon extending along said array and provided with type faces corresponding to said characters for imprinting them upon a web juxtaposed with said ribbon;

actuating means for displacing a selected number of said elements against said ribbon and said web; and a ribbon displacement mechanism engageable with said ribbon for advancing it past said array by a variable distance determined by the number of type elements displaced by said actuating means, said ribbon displacing mechanism including,

feed means engageable with said ribbon for displacing same, including a drum frictionally entraining said ribbon and a toothed ratchet coupled with said drum for rotating same, and; control means, responsive to an actuated type element to sense a number of type elements of said array for selectively varying said distance advanced by said ribbon in accordance with the number of type elements displaced by said actuating means, including a pawl engageable with said ratchet of said feed means for stopping same and a control member cooperating with said pawl and responsive to a displaced type element for determining the number of teeth by which said pawl is stopped.

5. The combination defined in claim 4 wherein said machine is a numeral-printing apparatus and said type elements are type bars representing respective orders of numerals to be printed, said array having a higher-order end and a lower-order end, said member being shiftable along said array in a direction from said higher-order end toward said lower-order end, said member being provided with abutment means engageable with the highestorder type bar to be displaced by said actuating means and forming a stop for said pawl permitting displacement thereof in a ratchet-stepping direction by a distance complementary to the degree of movement of said member in said direction from said higher-order end toward said lower-order end of said array.

6. The combination defined in claim 5 wherein said pawl is slidably displaceable in a direction transverse to the direction of displacement of said member and said member is provided with a plurality of stop steps staggered in the direction of displacement of said member and selectively engageable by aid pawl in accordance with said degree of movement.

7. The combination defined in claim 6 wherein said machine further comprises a platen extending parallel to said array and rotatable about a substantially horizontal axis to advance said web past said ribbon, said member being shiftable in a substantially horizontal plane, said drum being rotatable about a generally upright axis.

8. The combination defined in claim 5 wherein said member co-operates with said actuating means to prevent displacement thereby of type bars of a higher order than said highest-order type bar.

9. The combination defined in claim 4, further comprising cutting means for severing portions of said ribbon upon passage thereof past said array.

10. The combination defined in claim 9 wherein said machine is further provided with receptacle means for collecting the severed portions of said ribbon.

11. The combination defined in claim 9 wherein said' cutting means includes blade means displaceable transversely to said ribbon and coupled with said drum for actuation upon rotation thereof.

12. The combination defined in claim 11 wherein said drum is provided with a shaft connected therewith, said ratchet rotatably entraining said shaft, said cutting means further comprising a cam carried :by said shaft and camfollower means engaging said shaft and operatively connected with said blade means for actuating same.

13'. Ina machine of the character described having an ordinal series of digit type members each selectively adjustable from a normal position to a nonzero digit printing position, a ribbon extending along said type members for engagement with said members in a printing operation, and feed means for advancing said ribbon past said type members; a sensing member movable ordinally with respect to said type members and operable to detect the highest order type member adjusted to a nonzero printing position, actuating means cooperating with said sensing member to elfect a printing operation by said highest order adjusted type member and all lower order type members, and control means for said feed means, including said sensing member for advancing said ribbon past said type members a distance determined by the number of operated type members.

14. The invention according to claim 13; wherein said sensing member is movable ordinally with respect to said type members from higher to lower orders.

15. The invention according to claim 14; wherein said sensing member comprises a slide including an abutment operable to engage said highest order adjusted type member to arrest movement of said slide.

16. The invention according to claim 15; wherein said actuating means is normally operable with respect to all of said type members, and said slide is operable to disable said actuating means with respect to all type members of higher order than said highest order adjusted type member.

References Cited by the Examiner UNITED STATES PATENTS 1,391,424 9/ 1921 Spengler 101-227 1,660,638 2/1928 Warner 101-93 2,214,414 9/ 1940 Myers 197-153 2,634,533 4/1953 Hahn 101-336 2,714,850 8/1955 Kistner 101-96 2,734,614 2/1956 Page 197-151 2,815,110 12/1957 Carlson 197-151 2,868,346 1/1959 Kamp 197-151 3,151,546 10/1964 Clary et a1. 101-93 ROBERT E. PULFREY, Primary Examiner.

J. R. FISHER, Assistant Examiner,

UNITED STATES PATENT OFFICE CERTIFICATE- OF CORRECTION Patent No. 3, 304,859 February 21, 1967 Gustav Schenk It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 7, for "multitute" read multitude column 2, line 47, for "machine" read machine. column 3, line 58 for 'is" read it column 6, lines 52 and S3 and 67, and column 7, line 14, for "porportional", each occur rence, read proportional column 7, line 14, strike out "in"; column 8, line 47, for "acocrding" read according Signed and sealed this 7th day of November 1967 (SEAL) Attest:

Edward M. Fletcher, Jr. EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A RIBBON-DISPLACEMENT MECHANISM FOR A MACHINE HAVING A PLURALITY OF TYPE ELEMENTS ARRANGED IN CONSECUTIVE SPACES ALONG A PRINTING POSITION SELECTIVELY ENGAGEABLE WITH A RIBBON TO IMPRINT AT LEAST ONE CHARACTER OF A TYPE FACE CARRIED BY AT LEAST ONE OF SAID ELEMENTS UPON A WEB JUXTAPOSED WITH SAID RIBBON, SAID MECHANISM COMPRISING FEED MEANS ENGAGEABLE WITH SAID RIBBON FOR ADVANCING IT PAST SAID TYPE ELEMENTS; AND CONTROL MEANS FOR SAID FEED MEANS ENGAGEABLE WITH AN ACTUATED TYPE ELEMENT TO SENSE THE NUMBER OF TYPE ELEMENTS ACTUATED TO IMPRINT RESPECTIVE CHARACTERS UPON SAID WEB, FOR ADVANCING SAID RIBBON PAST SAID TYPE ELEMENTS BY A DISTANCE PORPORTIONAL TO SAID NUMBER OF ACTUATED TYPE ELEMENTS. 